Here is the full list of all 14 Tower Ball - there are Incremental Tower Defense achievements.
Shrink 1,000,000 Balls
Shrink 50,000,000 Balls
Shrink 100,000,000 Balls.. Maybe take a break?
Build 100 magnet towers
Build 100 acid towers
Build 100 saw towers
Build 100 electric towers
Build 100 bomb towers
Build 100 gun towers
Build 100 shrink ray towers
Spend 1,000,000 gems.
Shrink 10,000 Balls
Shrink 100 Balls